Filter assembly including pleat tip shapes

ABSTRACT

Solutions for efficiently filtering air for a machine are disclosed. In one embodiment, a filter element for a filter assembly of a rotary machine is provided. The filter element includes: a first set of pleats, each pleat including a first tip radius and a first spacing; and a second set of pleats, each pleat including a second tip radius and a second spacing, wherein the first and second set of pleats are positioned upon a continuous filter media.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to filters and, moreparticularly, to filter assemblies in a rotary machine.

Certain types of machines require a clean airflow in order to operateproperly and efficiently. One example of this type of machine is a gasturbine. During operation of a gas turbine, a compressor draws in airfrom the surrounding environment, compresses the air, and provides it toa combustion chamber. In the combustion chamber, the air is mixed with asupplied fuel that is ignited. This creates high temperature combustiongases that drive the gas turbine.

In order to maintain and/or increase the efficiency of the rotarymachine, the air from the surrounding environment must be filtered toremove unwanted particles so that clean, filtered air is provided to theremaining portions of the gas turbine system. The air flows through thefilter elements such that the unwanted particles are removed from theair. The media within the filter elements may be pleated to increase thefilter surface area, without substantially increasing the overall sizeand weight of the filter elements.

BRIEF DESCRIPTION OF THE INVENTION

Solutions for efficiently filtering air for a machine are disclosed. Inone embodiment, a filter element for a filter assembly of a rotarymachine is provided. The filter element includes: a first set of pleats,each pleat including a first tip radius and a first spacing; and asecond set of pleats, each pleat including a second tip radius and asecond spacing, wherein the first and second set of pleats arepositioned upon a continuous filter media.

A first aspect of the disclosure provides a filter element for a filterassembly of a rotary machine, the filter element comprising: a first setof pleats, each pleat including a first tip radius and a first spacing;and a second set of pleats, each pleat including a second tip radius anda second spacing, wherein the first and second set of pleats arepositioned upon a continuous filter media.

A second aspect provides a system comprising: a gas turbine; and afilter assembly operably connected to the gas turbine, the filterassembly comprising: a first set of pleats, each pleat including a firsttip radius and a first spacing; and a second set of pleats, each pleatincluding a second tip radius and a second spacing, wherein the firstand second set of pleats are positioned upon a continuous filter media.

A third aspect provides a system comprising: a gas turbine; a heatexchanger operably connected to the gas turbine; a steam turbineoperably connected to the heat exchanger; and a filter assembly operablyconnected to the gas turbine, the filter assembly comprising: a firstset of pleats, each pleat including a first tip radius and a firstspacing; and a second set of pleats, each pleat including a second tipradius and a second spacing, wherein the first and second set of pleatsare positioned upon a continuous filter media.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of this invention will be more readilyunderstood from the following detailed description of the variousaspects of the invention taken in conjunction with the accompanyingdrawings that depict various embodiments of the invention, in which:

FIG. 1 shows a partial perspective view of a filter element according toembodiments of the invention.

FIG. 2 shows a partial perspective view of a filter element according toembodiments of the invention.

FIG. 3 shows a schematic view of a system according to an embodiment ofthe invention.

FIG. 4 shows a schematic view of a combined-cycle system according to anembodiment of the invention.

FIG. 5 shows a schematic view of a combined-cycle system according to anembodiment of the invention.

It is noted that the drawings of the disclosure are not necessarily toscale. The drawings are intended to depict only typical aspects of thedisclosure, and therefore should not be considered as limiting the scopeof the disclosure. In the drawings, like numbering represents likeelements between the drawings.

DETAILED DESCRIPTION OF THE INVENTION

As indicated above, aspects of the invention provide for systems anddevices configured to efficiently filter air in a rotary machine byproviding a filter assembly including a plurality of sets of pleats.Each pleat may further include a first set of pleat tips and a secondset of pleat tips.

In the art of power generation systems, certain types of machinesrequire a clean airflow in order to operate properly and efficiently.One example of this type of machine is a gas turbine. During operationof a gas turbine, a compressor draws in air from the surroundingenvironment, compresses the air, and provides it to a combustionchamber. In the combustion chamber, the air is mixed with a suppliedfuel that is ignited. This creates high temperature combustion gasesthat drive the gas turbine.

In order to maintain and/or increase the efficiency, the air from thesurrounding environment must be filtered to remove unwanted particles sothat clean, filtered air is provided to the remaining portions of thegas turbine system. The air flows through the filter elements such thatthe unwanted particles are removed from the air. The media of the filterelements may be pleated to increase the filter surface area, withoutsubstantially increasing the overall size and weight of the filterelements.

Conventional filter elements include a continuous pleat shape andheight. A sharp pleat tip (i.e., a small pleat tip radius) will providemore open surface area to collected unwanted particles. However, thestructure of the filter element may be weakened by the sharp pleat tip.A more rounded pleat tip (i.e., a large pleat tip radius) will providebetter performance in other environments, but there is less apparentsurface area to collected unwanted particles.

Turning to the figures, embodiments of a filter element for a filterassembly are shown, where the varying shapes of the pleats may increasethe efficiency of a rotary machine, a turbine, and/or an overall powergeneration system. Specifically, referring to FIG. 1, a partialperspective view of a filter element 100 is shown according toembodiments of the invention. The filter element 100 may include a firstset of pleats 110 and a second set of pleats 120. The first set ofpleats 110 and the second set of pleats 120 are positioned upon asubstantially continuous filter media body. It is understood that asubstantially continuous body is one in which a plurality of elementsare configured to form an assembly which would be recognized as a singleunit, e.g., a component with a uniform surface or shape but for a set ofclearances/gaps between elements.

In the first set of pleats 110, each pleat includes a first tip radiusand a first spacing between each pleat. In the second set of pleats 120,each pleat includes a second tip radius and a second spacing betweeneach pleat. It is understood that the first tip radius is substantiallydifferent from the second tip radius. For example, as shown in FIG. 1,the first tip radius is less than the second tip radius. Further, it isunderstood that the first spacing may be substantially different fromthe second spacing. For example, as shown in FIG. 1, the first spacingis larger than the second spacing. Alternatively, it is understood thatthe first set of pleats 110 and the second set of pleats 120 may includethe same notional spacing. The tip radius of the pleats in both thefirst set of pleats 110 and the second set of pleats 120 may beapproximately 2 millimeters to approximately 0.5 millimeter. The spacingbetween each pleat in the first set of pleats 110 and the second set ofpleats 120 may be approximately 20 millimeters to 1 millimeter.

As clearly seen in FIG. 1, however, the pleat height for each pleat inthe first set of pleats 110 and the pleat height for each pleat in thesecond set of pleats 120 is substantially equal on the filter mediabody.

By sharpening the pleat tips (i.e., a smaller tip radius), and having alarger spacing between the pleats, the allowable space for the airflowthrough the filter element 100 is increased. This lowers the overallresistance to airflow, and the final pressure drop across the filter. Bylowering the final pressure drop across the filter, the filter may haveperformance benefits in certain environments; such as a higher dustholding capacity (DHC). However, by rounding the pleat tips (i.e., alarger tip radius), and having a smaller spacing between the pleats, alarger mechanical resistance is created, which acts as a benefit inother types of environment conditions. By including a plurality of setsof pleats 110, 120 in the filter element 100, the design of the filterelement 100 is optimized for a wider range of operational environments.

Turning now to FIG. 2, a partial perspective view of a filter element200 according to embodiments of the invention is shown. The filterelement 200 shown includes the first set of pleats 110 and second set ofpleats 120 of filter element 100 shown in FIG. 1. However, the filterelement 200 also includes a third set of pleats 130. Each pleat in thethird set of pleats 130, similar to each pleat in the first set andsecond set of pleats 110, 120, include a third tip radius andpotentially a third spacing. The third tip radius is substantiallydifferent from the first tip radius of the first set of pleats 110 andfrom the second tip radius of the second set of pleats 120. For example,the third tip radius may be less than the second tip radius, and thesecond tip radius may be less than the first tip radius. Further, thethird spacing of the third set of pleats 130 may be substantiallydifferent from the first spacing of the first set of pleats 110 and fromthe second spacing of the second set of pleats 120. For example, secondspacing may be larger than the third spacing, and the first spacing maybe larger than the second spacing. However, it is understood that anyorder of sizing for the first, second, and third tip radiuses and thefirst, second, and third spacings may be possible. Further, it isunderstood that filter element 100, 200 may include any number of setsof pleats.

Although the embodiments of filter element 100, 200 shown in FIGS. 1 and2 are shown to include a first sets of pleats 110 and a second set ofpleats 120 (and also a third set of pleats 130 (FIG. 2)), where eachpleat in the sets of pleats 110, 120, 130 are grouped together, it isunderstood that filter element 100, 200 may include alternating pleattips. For example, a pleat of the first set of pleats 110 may befollowed by a pleat of the second set of pleats 120, and this patternmay continue for the entire circumference of the filter element 100,200.

Filter element 100, 200 may be made from any now known or laterdeveloped filter material. For example, filter element 100, 200 may bemade from cellulose, blends of cellulose and polyester, glassmicrofiber, blends of glass microfibers and synthetic fibers, andcomposites. However, it is understood than any filter material may beused.

Turning now to FIG. 3, a schematic view of a system 350 according to anembodiment of the invention is shown. System 350 may include a gasturbine 300. However, as mentioned above, the embodiments of theinvention may be applied to any machine that benefits from improved airquality. For example, the embodiments of the invention may be similarlyapplied to different machines such as, but not limited to, gas, steam,or wind turbines, or internal combustion engines. System 350 may alsoinclude filter element 100 (or filter element 200, as discussed herein)that is operably connected to gas turbine 300. Gas turbine 300 may beoperably connected to a first load device 325. Load device 325 mayinclude, for example, a conventional electric generator, a compressor, apump, or any other conventional load device. Load device 325 and gasturbine 300 may be mechanically coupled by a shaft 330, which maytransfer energy between a drive shaft (not shown) of gas turbine 300 andload device 325.

Turning to FIG. 4, a schematic view of portions of a multi-shaftcombined cycle power plant 450 is shown. Combined cycle power plant 450may include, for example, gas turbine 300 operably connected to firstload device 325. Also shown in FIG. 4 is a heat exchanger 420 operablyconnected to gas turbine 300 and a steam turbine 400. System 450 mayinclude filter element 100 (or filter element 200, as discussed herein).Heat exchanger 420 may be fluidly connected to both gas turbine 300 andsteam turbine 400 via conventional conduits (numbering omitted). Heatexchanger 420 may be a conventional heat recovery steam generator(HRSG), such as those used in conventional combined cycle power systems.As is known in the art of power generation, HRSG may use hot exhaustfrom gas turbine 300, combined with a water supply, to create steamwhich is fed to steam turbine 400. Steam turbine 400 may optionally becoupled to a second load device 425 (via a second shaft 430). Secondload device 425 and second shaft 430 may operate substantially similarlyto load device 325 and shaft 330 described above. In another embodiment,shown in FIG. 5, a single shaft combined cycle power plant 550 mayinclude a single generator 325 coupled to both gas turbine 300 and steamturbine 400 via a single shaft 330.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A filter element for a filter assembly of arotary machine, the filter element comprising: a first set of pleats,each pleat including a first tip radius and a first spacing, wherein thefirst tip radius and the first spacing are at a circumference of thefilter element; and a second set of pleats, each pleat including asecond tip radius and a second spacing wherein the second tip radius andthe second spacing are at the circumference of the filter element,wherein the first and second set of pleats are positioned upon acontinuous filter media, wherein the first tip radius is less than thesecond tip radius, and wherein the first spacing is larger than thesecond spacing.
 2. The filter element of claim 1, wherein a pleat heightfor each pleat of the first set of pleats and a pleat height for eachpleat of the second set of pleats is substantially equal.
 3. The filterelement of claim 1, further comprising a third set of pleats, each pleatincluding a third tip radius and a third spacing.
 4. The filter elementof claim 3, wherein the third tip radius is larger than the second tipradius.
 5. The filter element of claim 4, wherein the second spacing islarger than the third spacing.
 6. A system comprising: a gas turbine;and a filter assembly operably connected to the gas turbine, the filterassembly comprising: a first set of pleats, each pleat including a firsttip radius and a first spacing, wherein the first tip radius and thefirst spacing are at a circumference of the filter assembly; and asecond set of pleats, each pleat including a second tip radius and asecond spacing wherein the second tip radius and the second spacing areat the circumference of the filter assembly, wherein the first andsecond set of pleats are positioned upon a continuous filter media,wherein the first tip radius is less than the second tip radius, andwherein the first spacing; is larger than the second spacing.
 7. Thesystem of claim 6, wherein a pleat height for each pleat of the firstset of pleats and a pleat height for each pleat of the second set ofpleats is substantially equal.
 8. The system of claim 6, furthercomprising a third set of pleats, each pleat including a third tipradius and a third spacing.
 9. The system of claim 8, wherein the thirdtip radius is larger than the second tip radius.
 10. The system of claim9, wherein the second spacing is larger than the third spacing.
 11. Asystem comprising: a gas turbine; a heat exchanger operably connected tothe gas turbine; a steam turbine operably connected to the heatexchanger; and a filter assembly operably connected to the gas turbine,the filter assembly comprising: a first set of pleats, each pleatincluding a first tip radius and a first spacing, wherein the first tipradius and the first spacing are at a circumference of the filterassembly; and a second set of pleats, each pleat including a second tipradius and a second spacing, wherein the second tip radius and thesecond spacing are at the circumference of the filter assembly, whereinthe first and second set of pleats are positioned upon a continuousfilter media, wherein the first tip radius is less than the second tipradius, and wherein the first spacing is larger than the second spacing.12. The system of claim 11, wherein a pleat height for each pleat of thefirst set of pleats and a pleat height for each pleat of the second setof pleats is substantially equal.
 13. The system of claim 11, furthercomprising a third set of pleats, each pleat including a third tipradius and a third spacing.
 14. The system of claim 13, wherein thethird tip radius is larger than the second tip radius, and wherein thesecond spacing is larger than the third spacing.